WO2013043858A1 - Procédés de rmn pour une analyse d'endotoxine - Google Patents

Procédés de rmn pour une analyse d'endotoxine Download PDF

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Publication number
WO2013043858A1
WO2013043858A1 PCT/US2012/056312 US2012056312W WO2013043858A1 WO 2013043858 A1 WO2013043858 A1 WO 2013043858A1 US 2012056312 W US2012056312 W US 2012056312W WO 2013043858 A1 WO2013043858 A1 WO 2013043858A1
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endotoxin
sample
water
relaxation rate
mixture
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PCT/US2012/056312
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English (en)
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Rahul K. Dhanda
Vyacheslav Papkov
Thomas Lowery
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T2 Biosystems, Inc.
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Priority to US14/345,803 priority Critical patent/US10620205B2/en
Priority to EP12833431.5A priority patent/EP2748651B1/fr
Publication of WO2013043858A1 publication Critical patent/WO2013043858A1/fr

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
    • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
    • G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
    • G01N33/573—Immunoassay; Biospecific binding assay; Materials therefor for enzymes or isoenzymes
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N24/00—Investigating or analyzing materials by the use of nuclear magnetic resonance, electron paramagnetic resonance or other spin effects
    • G01N24/08—Investigating or analyzing materials by the use of nuclear magnetic resonance, electron paramagnetic resonance or other spin effects by using nuclear magnetic resonance
    • G01N24/084—Detection of potentially hazardous samples, e.g. toxic samples, explosives, drugs, firearms, weapons
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/44—Arrangements or instruments for measuring magnetic variables involving magnetic resonance using nuclear magnetic resonance [NMR]
    • G01R33/48—NMR imaging systems
    • G01R33/50—NMR imaging systems based on the determination of relaxation times, e.g. T1 measurement by IR sequences; T2 measurement by multiple-echo sequences

Definitions

  • the present invention relates to the field of endotoxin analysis.
  • Endotoxin is a component of the cell wall in the outer membrane of gram-negative bacteria, and its activity is mainly attributed to LPS (lipopolysaccharide).
  • LPS lipopolysaccharide
  • endotoxin exists as a part of the outer membrane in the surface layer of gram negative bacteria.
  • endotoxin is liberated and is present in a free form in blood.
  • endotoxin When more than a certain level of endotoxin is present in blood, the endotoxin stimulates monocytes, granulocytes, etc., resulting in excessive production of inflammatory cytokines.
  • endotoxinemia accompanied by symptoms such as fever, sepsis, septic shock, multiple organ failure, etc.
  • detection of endotoxin in pharmaceuticals for injection, etc. is crucial, and thus the bacterial endotoxin test is prescribed by the Japanese, U.S., and European pharmacopeias. From the aspect of clinical diagnosis, precise measurement of blood endotoxin level is considered crucial for early diagnosis and therapeutic effect evaluation.
  • Examples of a conventional method for measuring endotoxin include the pyrogen test, in which a rabbit is treated with a direct injection of a test sample and measured for increase in body temperature that can be converted into the endotoxin level, and the Limulus test utilizing gelation of horseshoe crab amebocyte lysate triggered by endotoxin.
  • the method involving direct injection into a rabbit has problems in cost, length of time required to obtain the test results, and sensitivity, and for this reason, the Limulus test currently prevails as a method for measuring endotoxin.
  • a gelation of horseshoe crab amebocyte lysate is triggered by endotoxin.
  • the gelation process of horseshoe crab amebocyte lysate contains a Factor-C pathway specifically associated with endotoxin.
  • the Factor-C pathway is constituted by the following cascades. First, endotoxin firmly binds with
  • Factor-C Factor-C activated by binding with endotoxin (active Factor-C) activates Factor B.
  • activated Factor B activates a proclotting enzyme, resulting in production of a clotting enzyme.
  • This clotting enzyme partially hydrolyzes its substrate, i.e., coagulogen.
  • coagulogen a clotting protein
  • gelation occurs.
  • the Limulus test for measuring endotoxin utilizes the above-mentioned gelation process of horseshoe crab amebocyte lysate triggered by endotoxin.
  • a gel-clot technique a colorimetric technique using synthetic chromogenic substrates, and a kinetic turbidimetric techniques are established techniques used to evaluate gelation (i.e., clotting, see Figure 1).
  • New methods of detection are needed that can (i) increase the limit of detection of endotoxin, (ii) reduce the about of amebocyte lysate required for performing the assay, and/or (iii) allow for the monitoring of samples containing light scattering compositions.
  • the invention features a method of measuring the endotoxin level in a sample including the steps of: (a) mixing the sample with LAL reagent to form a mixture; (b) at a predetermined time following step (a), measuring the NMR relaxation rate of water in the mixture; and (c) on the basis of the NMR relaxation rate, determining the endotoxin level in the sample.
  • step (b) is repeated (e.g., over the course of 5, 10, 15, 20, 25, or 30 minutes) and the change in the NMR relaxation rate is observed at two or more time points following step (a).
  • the method can further include calculating the change in the NMR relaxation rate (e.g., the change observed between two or more measurements, such as the change in the NMR relaxation rate when compared to prior to, or in the first observation after, the completion of step (a), or a change relative to a threshold NMR relaxation rate value), and, on the basis of the change determining the endotoxin level in the sample.
  • the change in the NMR relaxation rate e.g., the change observed between two or more measurements, such as the change in the NMR relaxation rate when compared to prior to, or in the first observation after, the completion of step (a), or a change relative to a threshold NMR relaxation rate value
  • the endotoxin level is determined within 20 minutes of performing step (a) (e.g., within 5 ⁇ 2, 8 ⁇ 2, 10 ⁇ 5, 15 ⁇ 5, 20 ⁇ 5, 30 ⁇ 5, or 40 ⁇ 5 minutes).
  • the invention features a method for identifying the presence of endotoxin in a mixture including LAL reagent, the method including measuring a signal characteristic of the NMR relaxation rate of water in the mixture to produce NMR relaxation data, and on the basis of the NMR relaxation data determining whether the endotoxin is present in the mixture.
  • the invention features a method of identifying the presence of endotoxin in a sample by (i) mixing the sample with LAL reagent to form a mixture containing water and Factor-C capable of being activated by binding with endotoxin; (ii) following step (i), making a series of relaxation rate measurements of the water in the mixture capable of undergoing a clotting process to provide two or more decay curves, each decay curve characteristic of a time point in the process; (iii) applying a mathematical transform to the two or more decay curves to produce two or more magnetic resonance relaxation rates, each relaxation rate characteristic of a time point in the process; and (iv) based upon the two or more relaxation rates, determining whether endotoxin is present in the sample.
  • the invention features a method of identifying the presence of endotoxin in a sample by: (i) mixing the sample with LAL reagent to form a mixture containing water and Factor-C capable of being activated by binding with endotoxin; (ii) following step (i), making at least one relaxation rate measurement of the water in the mixture capable of undergoing a clotting process to provide one or more decay curves, each decay curve characteristic of a time point in the process; (iii) applying a mathematical transform to at least one decay curve to produce at least one magnetic resonance relaxation rate characteristic of a time point in the process; and (iv) based the relaxation rate, determining whether endotoxin is present in the sample.
  • step (iv) includes comparing the relaxation rate to a predetermined threshold value.
  • the invention further features a method of measuring the endotoxin level in a sample by: (i) mixing the sample with LAL reagent to form a mixture containing water and Factor-C capable of being activated by binding with endotoxin; (ii) following step (i), making at least one relaxation rate measurement of the water in the mixture capable of undergoing a clotting process to provide one or more decay curves, each decay curve characteristic of a time point in the process; (iii) applying a mathematical transform to at least one decay curve to produce at least one magnetic resonance relaxation rate characteristic of a time point in the process; and (iv) based the relaxation rate, determining the level of endotoxin present in the sample.
  • step (iv) includes comparing the relaxation rate to a predetermined threshold value (e.g., values from a predetermined dose -response curve for endotoxin).
  • the method can be capable of detecting 0.001 EU/mL, 0.0005
  • the mixture can include from 10% to 50% of the amount of LAL reagent typically used in a turbidometric assay (e.g., 10 ⁇ 5%, 15 ⁇ 5%, 20 ⁇ 5%, 25 ⁇ 5%, 30 ⁇ 5%, or 40 ⁇ 10% of the amount typically used in a turbidometric assay).
  • the amount of LAL reagent typically used in a turbidometric assay e.g., 10 ⁇ 5%, 15 ⁇ 5%, 20 ⁇ 5%, 25 ⁇ 5%, 30 ⁇ 5%, or 40 ⁇ 10% of the amount typically used in a turbidometric assay.
  • the sample can include a light scattering or light absorbing composition (e.g., the sample can be unsuitable for a turbidometric assay, but suitable for the methods described herein).
  • the NMR relaxation rate is selected from the group consisting of Tl, T2, T1/T2 hybrid, Ti rho , T 2rho , and T 2 * .
  • the invention features a method of measuring the endotoxin level in a sample including: (a) mixing the sample with LAL reagent to form a mixture containing Factor-C capable of being activated by binding with endotoxin; (b) following step (a), measuring a signal characteristic of the NMR relaxation rate of water in the mixture to produce NMR relaxation data; (c) determining from the NMR relaxation data a magnetic resonance parameter value or set of values, the value or set of values being responsive to Factor-C activation by the endotoxin in the mixture; and (d) on the basis of the result of step (c), determining the endotoxin level in the sample.
  • the mixture includes one or more populations of water and determining from the NMR relaxation data a magnetic resonance parameter value or set of values correlated to at least one population of water in the sample. In some embodiments, the mixture includes at least three populations of water.
  • the method can include fitting the measurements to an algorithm that distinguishes two or more separate water populations within the mixture, where each separate water population is characterized by one or more magnetic resonance parameters having one or more values.
  • the algorithm can be, without limitation, selected from a multi-exponential algorithm, a bi- exponential algorithm, a tri-exponential algorithm, a decaying exponential algorithm, a Laplace transform, a goodness-of-fit algorithm, an SSE algorithm, a least-squares algorithm, a non-negative least- squares algorithm, and any other algorithm described herein.
  • / Amp A exp (" " 72A) + Amp B ⁇ xp ⁇ - trnB) + Amp ⁇ xp ⁇ 72 ⁇ + 0(2)
  • / is the intensity of a measured value T2
  • ⁇ is time
  • Amp A is an extracted coefficient that indicates the degree to which the exponential term exp ( t/T2A) contributes to a measured T2 intensity
  • Amp B is an extracted coefficient that indicates the degree to which the exponential term exp (“ t/T2B) contributes to a measured T2 intensity
  • Amp c is an extracted coefficient that indicates the degree to which the exponential term exp ( t/T2C) contributes to a measured T2 intensity
  • T2A is an extracted relaxation time that indicates the contribution of a water population A to a measured T2 intensity
  • T2B is an extracted relaxation time that indicates the contribution of a water population B to a measured T2 intensity
  • T2C is an extracted relaxation time that indicates the contribution of a water population C to a measured T2 intensity
  • the signal arises from monitoring protons in water or monitoring oxygen atoms in water.
  • the NMR relaxation data is selected from Tl, T2, T1/T2 hybrid,
  • the invention features a method of measuring the endotoxin level in a sample including, the method including the steps of: (i) mixing the sample with LAL reagent to form a mixture containing Factor-C capable of being activated by binding with endotoxin; (ii) following step (i), measuring a series of signals characteristic of the NMR relaxation rate of water in the mixture to produce NMR relaxation data; and (iii) determining from the NMR relaxation data a time curve that is characteristic of Factor-C activation by the endotoxin in the mixture.
  • the time curve is a Tl time curve, a T2 time curve, or a hybrid T1/T2 time curve.
  • the invention features a method of comparing an endotoxin-induced clotting behavior of a sample measured using the NMR-based techniques of the invention with rheological change or clotting measured in an equivalent sample using a system known in the art.
  • 3D data set refers to a collection of measured and/or derived data points that can be assembled into a 3D plot that is characteristic of the changes in a sample undergoing a clotting process or dissolution process over a period of time.
  • a 3D plot derived from a 3D data set can depict the emergence and/or disappearance of different water populations within the sample and quantifies the intensities and relaxation times (e.g., T2 relaxation times) of these water populations at specific points in time or over ranges of time.
  • a first water population refers to a water population of an aqueous sample that is characterized by an initial amplitude when unclotted that changes with clotting.
  • a first water population may also refer to a water population referred to elsewhere in the application as population A.
  • the amplitude and T2 data extracted from a first water population are referred to as Amp A and T2A, respectively.
  • a second water population refers to a water population of an aqueous sample that is characterized by an initial amplitude when unclotted that changes with clotting.
  • the second water population having a characteristic relaxation time that is different from the first water population.
  • the second water population may be referred to elsewhere in the application as population B.
  • the amplitude and T2 data extracted from a second water population are referred to as Amp B and T2B, respectively.
  • a third water population refers to a water population of an aqueous sample that is characterized by a relaxation time that is different from the first water population and the second water population.
  • the third water population may be referred to elsewhere in the application as population C.
  • the amplitude and T2 data extracted from a third water population are referred to as Amp c and T2C, respectively.
  • algorithm refers to a mathematical routine used to process or transform data.
  • test refers to a method of monitoring endotoxin-induced clotting behavior.
  • clotting behavior refers to a parameter associated with an endotoxin- induced clot, a forming endotoxin-induced clot, or an endotoxin-induced clot undergoing dissolution (e.g., clotting time, clot strength, kinetic behavior of the clot, clot strength, etc.).
  • the term "clotting process” refers to a process in a liquid resulting in localized spatial change of the solvent water molecules within a sample and characterized by changes in the NMR relaxation rate of solvent water molecules within the aqueous liquid.
  • the aqueous liquid may have more than one population of solvent water molecules, each population characterized by an NMR relaxation parameter that varies as the aqueous sample undergoes the clotting process.
  • the aqueous liquid is in an NMR exchange regime that gives rise to a single population of solvent water molecules for which there is an observable relaxation rate shift during the clotting process.
  • the methods of the invention can be used to monitor an endotoxin-induced clotting process.
  • LAL reagent refers to both to amebocyte lysates obtained from horseshoe crabs (e.g., Limulus polyphemus, Carcinoscorpius rotundicauda, Tachypleudus tridentata, or Tachypleudus gigas) and to synthetic LAL reagents.
  • Synthetic LAL reagents include, for example, can include purified horseshoe crab Factor-C protein (naturally occurring or recombinant) and, optionally, a surfactant, as described in WO 03/002976.
  • One such reagent, "PyroGeneTM” is available from Cambrex Bio Science Walkersville, Inc. Reagents, such as those discussed in U.S. Patent Publication No.
  • LAL reagents preferably can be obtained from Cambrex Bio Science Walkersville, Inc. Lyophilized LAL reagent can be reconstituted with 1.4 mL of LAL reagent water (endotoxin-free water) and kept refrigerated until use.
  • a reagent kit that enables highly sensitive measurement of endotoxin using a recombinant Factor-C (trade name: PyroGene rFc, manufacturer: Lonza Walkersville, Inc., distributor: Daiichi Pure Chemicals Co., Ltd.) is commercially available.
  • magnetic resonance parameter refers to a relaxation rate or amplitude extracted from an NMR relaxation rate measurement.
  • NMR relaxation rate refers to any of the following in a sample: Tl, T2, Ti r ho, 2r ho, and T 2 . NMR relaxation rates may be measured and/or represented using T1/T2 hybrid detection methods.
  • the term "predetermined threshold value” refers to a standard parameter value or set of values, a standard time curve, or a standard signature curve that is derived from the methods of the invention and is characteristic of a particular rheological state or endotoxin level.
  • a predetermined threshold value can be obtained by measuring the NMR parameter values in, for example, samples with and without endotoxin.
  • the predetermined threshold value can be a predetermined value characteristic of the absence of clotting (i.e., such as in an endotoxin free standard).
  • the predetermined threshold value can be used to ascertain the amount of endotoxin in a sample at a particular time following the mixture of the endotoxin with an LAL reagent.
  • the threshold value can be a water relaxation rate.
  • the term "reader” or “T2reader” refers to a device for detecting coagulation- related activation including clotting of samples. T2readers may be used generally to monitor endotoxin- induced clotting in a sample. Such a device is described, for example, in International Publication No. WO 2010/051362, which is herein incorporated by reference.
  • the term "relative concentration” refers to the comparative concentration of one water population with respect to another (e.g., a second or third) water population.
  • the relative concentration of water population A may be two times (or five times, or ten times) greater than the concentration of water population B.
  • T1/T2 hybrid refers to any detection method that combines a Tl and a T2 measurement.
  • the value of a T1/T2 hybrid can be a composite signal obtained through the combination of, ratio, or difference between two or more different Tl and T2 measurements.
  • the T1/T2 hybrid can be obtained, for example, by using a pulse sequence in which Tl and T2 are alternatively measured or acquired in an interleaved fashion.
  • the T1/T2 hybrid signal can be acquired with a pulse sequence that measures a relaxation rate that is comprised of both Tl and T2 relaxation rates or mechanisms.
  • T2 signature refers to a curve established by applying a mathematical transform (e.g., a Laplace transform or inverse Laplace transform) to a decay curve associated with a relaxation rate parameter at a discrete time point or over a set time duration during a rheological event.
  • T2 signature curves provide information about the relative abundance of multiple water populations in a clot.
  • T2 signatures may be used advantageously to assess, in real time, a discriminated endotoxin contamination or level in a sample.
  • a T2 signature may be a two dimensional (intensity versus T2 value or T2 value versus time) or three dimensional representation (intensity versus T2 value versus time).
  • the T2 values in the two- or three dimensional representation may be replaced with or compared to other NMR signals such as Tl, T1/T2 hybrid, T lrho> T 2r 0 and T 2 .
  • Figure 1 is a chart depicting LAL procedures for monitoring and measuring endoxtoxin in a sample.
  • the sample can be a negative control (water blank), an endotoxin standard (e.g., for producing a standard curve), a test sample (for determining whether, or how much, endotoxin is present in the sample, and/or a test sample spiked with endotoxin.
  • lyophilized LAL is typically reconstituted with LAL Reagent Water (endotoxin-screened water).
  • the endotoxin standard can be available as a lyophilized lipopolysaccharide to be reconstituted with LAL Reagent Water. See Example 2.
  • FIG. 2 is a graph depicting the T2 relaxation rate of water as a function of time following the initiation of the clotting reaction by addition of varying levels of endotoxin standard to the LAL reagent (see Example 2).
  • An increase in the change is the T2 relaxation rate of water over time was observed with increasing levels of endotoxin.
  • the T2 relaxation rate has a dose-dependent response to endotoxin levels and adequate resolution of the positive samples from the zero as low as 0.005 EU/mL. The data was collected on two readers over the period of 3.5hours.
  • Figure 3 is a graph depicting the percent change in the T2 values as a function of time following the initiation of the clotting reaction by addition of varying levels of endotoxin standard to the LAL reagent (see Example 2).
  • the percent change in the T2 value at a predetermined time point can be used to determine the concentration of endotoxin in a sample.
  • Figures 4A and 4B are plots depicting the correlation between endotoxin level versus the clotting time for a predetermined percent change in T2 value (see Example 2).
  • Figure 4 A depicts the correlation for a 2% change in T2.
  • Figure 4B depicts the correlation for a 0.2% change in T2. The strong correlation observed for small changes in T2 permit rapid detection of endotoxin in a sample.
  • FIG. 5 is a graph depicting the T2 relaxation rate of water as a function of time following the initiation of the clotting reaction by addition of varying levels of endotoxin standard (down to 0.0001 EU) to the LAL reagent (see Example 2).
  • the T2 relaxation rate has a dose-dependent response to endotoxin levels and adequate resolution of the positive samples from the zero as low as 0.0001 EU/mL.
  • Figure 6 is a graph depicting the T2 relaxation rate of water as a function of time following the initiation of the clotting reaction by addition of varying amounts of l,3- -D-glucan (see Example 3).
  • the resulting dose response curve for l,3- -D-glucan in buffer shows that 100 pg/mL of l,3- -D-glucan was detected in less than 45 minutes.
  • a boxcar smoothing function was applied to the T2 signal.
  • the methods of the invention provide a simple and rapid method for detection and measurement of the bacterial cell-wall toxin endotoxin and fungal cell-wall toxin 1,3- ⁇ -D-glucan. These can be measured by means of the Limulus Amoebocyte Lysate (LAL) clotting response to these toxins in solution.
  • LAL Limulus Amoebocyte Lysate
  • the sensitivity of NMR relaxation rates to clot formation in solution can be used to detect and measure endotoxin by means of the LAL gelation reaction. When the LAL polymerizes, water diffusion is effected, thereby altering the measured NMR relaxation values.
  • the methods and devices of the invention can be used to quickly and efficiently assess endotoxin levels in a sample. Clotting Initiation
  • clotting may be initiated using a Factor-C containing reagent.
  • a suitable Factor C-containing reagent may be a horseshoe crab amebocyte lysate conventionally used for the Limulus test.
  • Such a horseshoe crab amebocyte lysate is not particularly limited as long as it is derived from, for example, hemocytes of horseshoe crabs belonging to the Limulus sp., the Tachypleus sp. or the Carcinoscorpius sp., and it can produce the clotting enzyme via a reaction with endotoxin. Therefore, a commercially available Limulus reagent (LAL reagent), or a Limulus reagent (LAL reagent) provided in a kit for endotoxin measurement can be suitably used.
  • LAL reagent Limulus reagent
  • LAL reagent Limulus reagent
  • a recombinant Factor C derived from a recombinant gene prepared based on all or a part of the horseshoe crab Factor C gene.
  • a suitable example of the recombinant Factor C may be the recombinant Factor C provided in the commercially available PyroGene rFc (manufactured by Lonza Walkersville and Inc., distributed by Daiichi Pure Chemicals Co., Ltd.).
  • the recombinant Factor C may be obtained by preparing an expression vector having the horseshoe crab Factor C gene inserted thereinto according to a known genetic engineering method, introducing the vector into appropriate host cells to achieve expression of a recombinant protein, and purifying the protein.
  • the methods of the invention can be performed using a reduced amount of C-containing reagent.
  • the amount used with the methods of the invention can be about 10% to 50% of the typical amount otherwise used. This is because of the increased sensitivity of the assay of the invention. About 10% to 50% of the typical amount is equivalent to approximately 0.375 to 2.2 mg/mL of protein derived from horseshoe crab amebocyte lysate.
  • Standard radiofrequency pulse sequences for the determination of nuclear resonance parameters are known in the art, for example, the Carr-Purcell-Meiboom-Gill (CPMG) is traditionally used if relaxation constant T 2 is to be determined.
  • CPMG Carr-Purcell-Meiboom-Gill
  • T 2 relaxation constant
  • Nuclear magnetic resonance parameters that can be obtained using the methods of the present invention include but are not limited to Tl , T2, T1/T2 hybrid, T lrho> T 2r 0 and T 2 .
  • at least one of the one or more nuclear resonance parameters that are obtained using the methods of the present invention is spin-spin relaxation constant T2.
  • NMR-based diagnostics As with other diagnostics and analytical instrumentation, the goal of NMR-based diagnostics is to extract information from a sample and deliver a high-confidence result to the user. As the information flows from the sample to the user it typically undergoes several transformations to tailor the information to the specific user. This can be achieved by processing the NMR relaxation signal into one or more series of component signals representative of the different populations of water molecules present, e.g., in a sample that is undergoing endotoxin-induced clotting. For example, NMR relaxation data, such as T2, can be fit to a decaying exponential curve defined by the following equation:
  • Methods that have been successfully applied and may be applied in the processing of the raw data obtained using the methods of the present invetion include Laplace transforms, algebraic methods, graphical analysis, nonlinear least squares (of which there are many flavors), differentiation methods, the method of modulating functions, integration method, method of moments, rational function approximation, Pade- Laplace transform, and the maximum entropy method (see Istratov, A. A. & Vyvenko, O. F. Rev. Sci. Inst. 70: 1233 (1999)).
  • Other methods, which have been specifically demonstrated for low field NMR include singular value decomposition (Lupu, M. & Todor, D. Chemometrics and Intelligent Laboratory Systems 29: 11 (1995)) and factor analysis.
  • Bruker minispec uses the publicly-available CONTIN algorithm for some of their analysis.
  • the relaxation times are expected to be discrete values unique to each sample and not a continuous distribution, therefore programs like CONTIN are not needed although they could be used.
  • the code for many other exponential fitting methods are generally available (Istratov, A. A. & Vyvenko, O. F. Rev. Sci. Inst. 70: 1233 (1999)) and can be used to obtain medical diagnostic information according to the methods of the present invention. Information is available regarding how the signal to noise ratio and total sampling time relates to the maximum number of terms that can be determined, the maximum resolution that can be achieved, and the range of decay constants that can be fitted.
  • the methods of the invention can be used on a benchtop NMR relaxometer, benchtop time domain system, or NMR analyzer (e.g., ACT, Bruker, CEM Corporation, Exstrom Laboratories, Quantum Magnetics, GE Security division, Halliburton, HTS-111 Magnetic Solutions, MR Resources, NanoMR, NMR Petrophysics, Oxford Instruments, Process NMR Associates, Qualion NMR Analyzers, SPINLOCK Magnetic Resonance Solutions, or Stelar, Resonance Systems).
  • ACT Bruker
  • CEM Corporation CEM Corporation
  • Exstrom Laboratories Quantum Magnetics
  • GE Security division Halliburton
  • HTS-111 Magnetic Solutions MR Resources
  • NanoMR NMR Petrophysics
  • Oxford Instruments Process NMR Associates
  • Qualion NMR Analyzers SPINLOCK Magnetic Resonance Solutions
  • SPINLOCK Magnetic Resonance Solutions or Stelar, Resonance Systems
  • the CPMG pulse sequence used to collect data with a T2reader is designed to detect the inherent T2 relaxation time of the sample. Typically, this is dictated by one value, but for samples containing a complex mixture of states (e.g., a sample undergoing a clotting process or dissolution process) in a slow- exchange regime, a distribution of T2 values can be observed. In this situation, the signal obtained with a CPMG sequence is a sum of exponentials.
  • One solution for extracting relaxation information from a T2reader output is to fit a sum of exponentials in a least-squares fashion. Practically, this requires a priori information on how many functions to fit.
  • a second solution is to use the Inverse Laplace transform (ILT) to solve for a distribution of T2 values that make up the exponential signal observed. Again, the results of the CPMG sequence S(t), is assumed to be the sum of exponentials
  • A is the amplitude corresponding to the relaxation time constant T2 ; . If, instead of a discrete sum of exponentials, the signal is assumed to be a distribution of T2 values, the sum over states can be represented by (5) This has the same functional form as the ILT
  • An inverse Laplace transform may also be used in the generation of a 3D data set.
  • a 3D data set can be generated by collecting a time series of T2 decay curves and applying an inverse Laplace transform to each decay curve to form a 3D data set.
  • a 2D inverse Laplace transform can be applied to a pre-assembled 3D data set to generate a transformed 3D data set describing the distribution of T2 times.
  • r a and r b correspond to the relaxation rates of water in the two populations;
  • f a and 3 ⁇ 4 correspond to the fraction of nuclei in each phase;
  • ⁇ ⁇ and x b correspond to residence time in each phase; and
  • a (1/ ⁇ ⁇ ) + (1/ ⁇ 3 ⁇ 4 ) corresponds to the chemical exchange rate.
  • r 2 ( l/2) (r a + r h + a) + (1/2) / ⁇ r b - r a + ⁇ n
  • the invention also features the use of a pulsed field gradient or a fixed field gradient in the collection of relaxation rate data.
  • the invention further features the use of the techniques of diffusion- weighted imaging (DWI) as described in Vidmar et al. (Vidmar et al., NMR Biomed. 23: 34-40 (2010)), which is herein incorporated by reference, or any methods used in porous media NMR (see, e.g, Bergman et al., Phys. Rev. E 51 : 3393-3400 (1995), which is herein incorporated by reference).
  • DWI diffusion- weighted imaging
  • the methods of the invention can be carried out in the presence of a paramagnetic agent (i.e., gadolinium, manganese, magnetic particles, etc.) added, e.g., to the sample prior to initiating clotting.
  • a paramagnetic agent i.e., gadolinium, manganese, magnetic particles, etc.
  • the paramagnetic reagent can be used to shorten the relaxation times of the water molecules, permitting the data acquisition to proceed with shorter dwell times.
  • the magnetic particles that can be used in the methods of the invention include those described, e.g., in U.S. Patent No. 7,564,245 and U.S. Patent Application Publication No. 2003-0092029, each of which is incorporated herein by reference.
  • the particles have high relaxivity owing to the
  • the magnetic particles typically include metal oxide crystals of about 1-25 nm, e.g., about 3-10 nm, or about 5 nm in diameter per crystal.
  • the magnetic particles can also include a polymer component in the form of a core and/or coating, e.g., about 5 to 20 nm thick or more.
  • the overall size of the magnetic particles can be, e.g., from 20 to 50 nm, from 50 to 200 nm, from 100 to 300 nm, from 250 to 500 nm, from 400 to 600 nm, from 500 to 750 nm, from 700 to 1,200 nm, from 1 ,000 to 1 ,500 nm, or from 1 ,500 to 2,000 nm.
  • Magnetic particle size can be controlled by adjusting reaction conditions, for example, by using low temperature during the neutralization of iron salts with a base as described in U.S. Patent No. 5,262,176. Uniform particle size materials can also be made by fractionating the particles using centrifugation, ultrafiltration, or gel filtration, as described, for example in U.S. Patent No. 5,492,814. Magnetic particles can also be synthesized according to the method of Molday (Molday, R. S. and D. MacKenzie, "Immunospecific ferromagnetic iron-dextran reagents for the labeling and magnetic separation of cells," J. Immunol. Methods, 52:353 (1982)), and treated with periodate to form aldehyde groups.
  • the aldehyde -containing magnetic particles can then be reacted with a diamine (e.g., ethylene diamine or hexanediamine), which will form a Schiff base, followed by reduction with sodium borohydride or sodium cyanoborohydride.
  • the magnetic particles can be formed from a ferrofluid (i.e., a stable colloidal suspension of magnetic particles).
  • the magnetic particle can be a composite of multiple metal oxide crystals of the order of a few tens of nanometers in size and dispersed in a fluid containing a surfactant, which adsorbs onto the particles and stabilizes them, or by precipitation, in a basic medium, of a solution of metal ions.
  • Suitable ferrofluids are sold by the company Liquids Research Ltd. under the references: WHKS1S9 (A, B or C), which is a water-based ferrofluid comprising magnetite (Fe 3 0 4 ), having particles 10 nm in diameter; WHJS1 (A, B or C), which is an isoparaffin-based ferrofluid comprising particles of magnetite (Fe 3 0 4 ) 10 nm in diameter; and BKS25 dextran, which is a water-based ferrofluid stabilized with dextran, comprising particles of magnetite (Fe 3 0 4 ) 9 nm in diameter.
  • the magnetic particles are typically a composite including multiple metal oxide crystals and an organic matrix, and having a surface decorated with functional groups (i.e., amine groups or carboxy groups) for linking binding moieties to the surface of the magnetic particle.
  • the magnetic particles useful in the methods of the invention include those commercially available from Dynal, Seradyn, Kisker, Miltenyi Biotec, Chemicell, Anvil, Biopal, Estapor, Genovis, Thermo Fisher Scientific, JSR micro, Invitrogen, and Ademtech, as well as those described in U.S. Patent Nos. 4,101,435; 4,452,773; 5,204,457; 5,262,176; 5,424,419; 6,165,378; 6,866,838; 7,001,589; and 7,217,457, each of which is incorporated herein by reference.
  • the methods of the invention can be performed in the presence of particles that contain multiple superparamagnetic iron oxide cores (5-15 nm diameter) within a single larger polymer matrix or ferrofluid assembly (100 nm-1200 nm total diameter, such as particles having an average diameter of 100 nm, 200 nm, 250 nm, 300 nm, 500 nm, 800 nm, or 1000 nm), or by using a higher magnetic moment materials or particles with higher density, and/or particles with higher iron content.
  • particles that contain multiple superparamagnetic iron oxide cores 5-15 nm diameter
  • a single larger polymer matrix or ferrofluid assembly 100 nm-1200 nm total diameter, such as particles having an average diameter of 100 nm, 200 nm, 250 nm, 300 nm, 500 nm, 800 nm, or 1000 nm
  • a higher magnetic moment materials or particles with higher density, and/or particles with higher iron content such as particles having an average diameter of 100 nm, 200
  • NMR-based methods of the invention described herein may be used in a variety of applications where a substance or mixture of substances is undergoing testing for endotoxin
  • the methods of the invention can be performed in conjunction with other systems, devices, and/or methods for the rapid detection of analytes or an analyte concentration in a sample.
  • the methods of the invention can be performed in conjunction with the systems, devices, and methods described in PCT Publication No.
  • PCT/US2011/56936 filed October 19, 2011, and incorporated herein by reference, which can include one or more of the following: (i) assay for endotoxin in water, diasylate, pharmaceutical preparations, or biopharmaceutical preparations; (ii) end-product testing of human injectable or animal injectable fluids (including drugs, medicaments, solutions), or medical devices; (iii) assay for endotoxin in raw materials used in production, including water; (iv) assay for endotoxin for in- process monitoring of endotoxin levels for any medical procedure; (v) assay biological samples (e.g., blood, sweat, tears, urine, saliva, semen, serum, plasma, cerebrospinal fluid (CSF), feces, vaginal fluid or tissue, sputum, nasopharyngeal aspirate or swab, lacrimal fluid, mucous, or epithelial swab (buccal swab), tissues, organ
  • the methods and device of the invention are used to detect bacterial endotoxin, i.e., cell wall material from gram-negative bacteria. Endotoxin is capable of causing high fevers in humans, and, consequently, injectable drugs and medical devices that contact the blood are frequently tested for the presence of endotoxin.
  • a clotting-based assay for detecting endotoxin relies upon the reaction between bacterial endotoxin and a specific lysate used in the assay.
  • a lysate derived from the circulating amebocytes of the horseshoe crab Limulus polyphemus is a particular lysate that can be used.
  • the lysate is introduced to a sample to be tested for the presence of endotoxin. If a gel is formed, via a clotting process, endotoxin is deemed to be present. The formation and properties of such a gel are monitored by any of the NMR-based methods described herein.
  • the goal of the study is to determine the applicability of magnetic relaxation as a means for detecting endotoxin-induced clot formation.
  • This study utilizes Lonza Limulus Amebocyte Lysate (LAL) reagent(s).
  • LAL Lonza Limulus Amebocyte Lysate
  • the clotting cascade of Horseshoe crabs is a primitive defense mechanism to infection by bacteria and fungi.
  • LPS Lipopolysaccharide
  • Lonza LAL reagents were used to confirm the performance of the gel clot and/or turbidimetric assays in response to known amounts of endotoxin.
  • the LAL reagents and accessories used to perform the assays are listed in Table 1.
  • the endotoxin was reconstituted in 5 mL LAL reagent water (LRW) (results in 2000 EU/ml solution) and vortexed 30 minutes. A series of dilutions was performed to generate standard endotoxin solutions (i.e., from 200 EU/mL solution to 0.001 EU/mLsolution).
  • LAL reagent water results in 2000 EU/ml solution
  • a series of dilutions was performed to generate standard endotoxin solutions (i.e., from 200 EU/mL solution to 0.001 EU/mLsolution).
  • the LAL reagent was reconstituted in LAL reagent water, and the contents swirled gently until dissolution.
  • Each tube was prepared by adding the LAL reagent solution to the test sample containing a predetermined amount of endotoxin (or a blank).
  • the reaction was monitored in a T2 magnetic reader, holding test temperature constant (+/-1°C) throughout assay. All T2MR data was processed using the following signal acquisition settings and signal processing algorithm: all data was acquired on two T2MR readers. Signal acquisition settings: 45 us tau, 6 sec recycle delay, 6 sec total echo time, 300 T2 measurements every -14 seconds. Signal processing settings: smoothing function of 16 or 22 moving boxcar average, DT2 normalization to either the T2 value at 2 min, 5min, or the maximum T2 value. The "time to clot" was determined at threshold changes in T2 of 0.2%, 0.5% or 2%.
  • T2 relaxation rate of water over time was observed with increasing levels of endotoxin (see Figures 2, 3, and 5).
  • the T2 relaxation rate has a dose -dependent response to endotoxin levels and adequate resolution of the positive samples from the zero to as low as 0.005 EU/mL (see Figure 2) or 0.0001 EU/mL (see Figure 5).
  • the data can be presented as the percent change in the T2 values as a function of time following the initiation of the clotting reaction by addition of varying levels of endotoxin standard to the LAL reagent (see Figure 3).
  • the percent change in the T2 value at a predetermined time point can be used to determine the concentration of endotoxin in a sample.
  • the magnetic relaxation approach for endotoxin detection provides a sensitivity advantage because the measurement probe is the water molecules in the sample. When diffusion properties of water change, then the T2 signal changes. This method of measurement can be highly sensitive due to the sensitivity of water to changes in the solution at the molecular level. It is believed that this is the underlying principle for the superior sensitivity of magnetic relaxation detection for endotoxin, as compared to optical turbidometric measurements that require a significant fraction of the solution to scatter or absorb light.
  • l,3" -D-glucan is a component of the fungal cell wall and can be used for systematic screening and identification of significant fungal infections.
  • PYROGENT-5000 reagents (Lonza) were used (as described in Example 2) with detection methods of the invention to generate a dose response curve for l,3" -D-glucan in buffer. The results are depicted in Figure 6, demonstrating that 100 pg/mL of 1,3- ⁇ - ⁇ - glucan was detected in less than 45 minutes.
  • a boxcar smoothing function was applied to the T2 signal. In comparison to endotoxin detection, smaller T2 changes were observed. This smaller change in T2 was likely due to the lack of specificity of the LAL reagent for the clotting initiator. Sensitvity and specificity can be improved with assay optimization.
  • Example 4 Data extraction algorithms for interpreting clotting in a sample in the slow exchange rate regime
  • the clotting process can be monitored as described in Example 2, and the data output from the T2reader can be processed using a three-step method of performing a bi-exponential fit, plotting and checking, feature extraction, T2 signature curves, relaxation spectra, and 3D plot of water populations in a clot (all described below).
  • the curves can be fitted to a bi-exponential equation using start points (e.g., seeds) for AmpA, AmpB, T2A, and T2B with fixed seeds used for the first five time points.
  • the seed for the sixth time point can be obtained from the average of the first five time points.
  • time points can be seeded with output from the previous time point. Negative values for parameters can be not allowed.
  • the data can be fit initially in the middle of the time series, working similarly to the ends.
  • the goodness-of-fit term can be computed by taking the sum of squares of the fit residuals, excluding non-negative values, called SSE.
  • the parameters AmpA, AmpB, T2A, and T2B can be binned into their respective categories to create a text file.
  • the plotted curves can be measured to extract the values associated with clotting behaviors, such as clotting time.
  • Data extraction can be carried out using any of a variety of methods known in the art. For example, metrics can be derived from the curve shape of the resulting data and/or calculated from the value of one or more NMR parameters.
  • NMR data can be processed to create a T2 signature curve displaying distinct signals (i.e.
  • the T2 signature curves are created by applying a mathematical transform (e.g., a Laplace transform or inverse Laplace transform) to a decay curve associated with T2 at a time point during a clotting event.
  • a mathematical transform e.g., a Laplace transform or inverse Laplace transform
  • T2readers can be configured to measure Tl measurements.
  • Tl measures different physical properties of the hydrogen atom spin system in the sample. Therefore, Tl data provides alternative and complementary information about endotoxin clotting compared to T2 data. While conventional Tl measurements are time consuming (2-3 minutes) due to the step-wise nature of acquiring the Tl signal, a z-refocused echo (ZRE) method can be used to acquire Tl within less than 5 seconds.
  • ZRE z-refocused echo
  • Tl relaxation measurements can be used in the endotoxin detection assays of the invention.
  • T1/T2 hybrid detection methods are known in the art (Edzes, . Magn. Reson. 17: 301-313, 1975; Sezginer et al., . Magn. Reson. 92: 504-527, 1991, which are hereby incorporated by reference). These methods and related methods may be used in the endotoxin detection assays of the invention.
  • Tl is typically sampled by means of an inversion-recovery sequence.
  • Inversion recovery sequences can take several minutes to acquire depending on the precision of the measured relaxation time that the user wants to achieve, which is dictated by the number of data measurements used in the pulse sequence. The details of the inversion recovery sequence will not be described here, as they can be looked up in any standard NMR textbook.
  • a T1ZRE pulse sequence allows for the measurement of Tl over the time required for the magnetization to completely relax. (-3-5 x Tl). This is achieved by inverting the magnetization with a 180° pulse and then sampling the magnetization while the magnetization returns to equilibrium by measuring its magnitude and returning it to its original -z position with a series of pulses.
  • the time that it takes to sample the magnetization is called x c , and the time between samplings is ⁇ ⁇ .
  • the time after the start of x c until the actual measurement is x m .
  • the measured relaxation constant is a combination of R 2 and Ri and is referred to as R 12 . The three terms are related by
  • x r will depend on the total number of points and the total duration of the measurement. For T2COAG measurements, it was 30 points over ⁇ 3 seconds for a x r of 100 milliseconds.
  • the x c term can be calculated from the pulse sequence and is essentially equivalent to 3xtau or 750 ⁇ . Accordingly, the p term is equal to 0.0075 and the measured relaxation, or hybrid, T1/T2 (hT12) term should primarily be Tl. Sezginer et al.
  • Tl is Tl
  • T b is the duration between the two measurements, is half of the inter- echo delay or tau
  • T 2 is the measured T2 time.
  • the inventive concept is directed to rapid acquisition of magnetic resonance relaxation measurements.
  • Other types of magnetic resonance pulse sequences can be used to monitor the bulk hydrogen signal in the sample during coagulation. Examples include T2, Tl, T1/T2 hybrid times, their inverse terms of R2, RI, R12, and pulsed NMR measurements commonly used for materials analyses on relaxometers such as free induction decay (FID) based analyses, fast Fourier transform based analyses (FFT). FID analysis commonly discriminates between rapidly decaying signals and slowly decaying signals. The intensities of these two signals can be compared, as can their decay constants.
  • FID free induction decay
  • FFT fast Fourier transform based analyses
  • pulse sequences have been commonly used for fat analysis, fat content and solid to liquid ratio, solid fat to liquid ratio, hydrogen content determination, oil content, solids content, and total fat content determinations, oil water emulsions, and fat and moisture determinations. Similar real-time or kinetic measurements can be performed with those NMR parameters on samples that are undergoing an endotoxin-induced clotting reaction.
  • the invention features data processing tools to transform the raw relaxation NMR data into a format that provides signature curves characteristic of a clotting process.
  • Possible transforms include the Laplace or inverse Laplace transform (ILT).
  • the data for each T2 measurement may be transformed from the time dimension where signal intensity is plotted verses time to a "T2 relaxation" dimension.
  • the ILT provides not only information about the different relaxation rates present in the sample and their relative magnitudes but also reports on the breadth of distribution of those signals.
  • Each acquired T2 relaxation curve has a corresponding two dimensional signature that maps all of the different populations of water, or different T2 relaxation environments, that water is experiencing in the sample. These curves can be compiled to form a 3D data set by stacking the plots over the duration of the clotting time dimension. This generates a 3D surface that shows how the different populations of water change as a function of time.
  • the data gathered using the methods of the invention can be represented using 3D plots generated from different NMR parameters. Additional dimensions can be added by looking at specific patient types or clotting curve types. Data reduction methods can be used to simplify the complex information that is available. Such techniques as principal component analyses (PC A), automated feature extraction methods, or other data handling methods can be used. Ideally, a library of signatures, 2D, and 3D plots can be generated for a wide variety of clinical conditions. For example, two dimensional (intensity versus T2 value or T2 value versus time) or three dimensional representations (intensity versus T2 value versus time). The T2 values in the two- or three dimensional representation may be replaced with or compared to other NMR signals such as Tl, T1/T2 hybrid, T lrho> T 2r 0 and T 2 .
  • Tl intensity versus T2 value or T2 value versus time
  • T2 values in the two- or three dimensional representation may be replaced with or compared to other NMR
  • an endotoxin-induced clotting process within a sample is assessed by an NMR parameter extracted from one or more free induction decay (FID) signals obtained from the sample.
  • an NMR parameter can be extracted from the signal to noise ratio of an FID, from a comparison of an FID to a predetermined threshold, or from the integration of an FID.
  • the NMR parameters obtained by the method can be used to characterize the clotting process, improve sensitivity, or reduce the amount of time needed to produce a test result.
  • T2 relaxation spectra can be used to identify and monitor different populations of water in a sample undergoing clotting.
  • 3D representations of the T2 data in a sample undergoing a clotting process may be generated using the methods of the invention.
  • the dimensions of the generated 3D plots correspond to a relaxation time (e.g., T2 or 1/T2) dimension, an intensity or amplitude dimension, and a time dimension.
  • the time dimension represents the time over which the clotting process has proceeded or is proceeding.
  • the 3D plots obtained from endotoxin-induced clotting can exhibit a variety of topographical features that correspond with separate water populations in different physical and/or chemical environments within the sample.
  • the 3D plots and the data used to generate the 3D plots may be mined for biomarkers or clotting behaviors associated with the sample.
  • the 3D plots or the data used to generate the 3D data plots may also be used to discover new biomarkers.
  • the 3D data associated with a 3D plot of a clotting sample can be used to generate a Dashboard
  • a similar dashboard display can be generated using the methods of the invention for an endotoxin assay.
  • the information contained within the different topographical features and water populations evident in the 3D plot may be associated with particular biomarkers and clotting behaviors.
  • a variety of methods can be used to extract the biomarkers or clotting behaviors from the 3D data set. For example, the slope or curvature of a topographical feature of a 3D plot may be correlated with a clotting behavior.
  • a cross-section of a 3D plot may also be used to calculate a clotting behavior.
  • a cross-section of a 3D plot showing T2 time as a function of intensity at a given time depicts the various water populations present in a sample at a given time.
  • the features of a T2 relaxation spectrum can be mined for a range of clotting behaviors.
  • the integration of a particular topographical feature, such as the volume of a particular feature, or curve from a cross-section of a 3D plot may also be useful in establishing a clotting behavior (e.g. clot strength).
  • Clotting behaviors may also be extracted through the integration of a range of T2 relaxation spectra collected at sequential or disparate time points.
  • the 3D plots can be used to identify a feature characteristic of clot behavior.
  • the feature can be one that is measured without 3D analysis, such as via pulse sequence for selectively monitoring a water population having an average T2 relaxation rate of about 400 milliseconds or 1 ,000 milliseconds at a particular time post clot initiation.
  • the water population is measured exclusive of other water populations in the sample.
  • T2 relaxation curve including the range of T2 values associated with a particular signal, may vary based on the instrument (e.g., a T2reader or a Bruker minispec) used to collect data.
  • the range of T2 values for a given sample may depend on the material used to construct the tubes (e.g., plastic or glass) containing the sample during T2 measurements.
  • the invention encompasses the use of any magnetic resonance instrument and any sample container in the collection of a 3D data set used in the analysis of a sample.

Abstract

L'invention concerne un procédé de surveillance d'un processus de coagulation en mesurant un signal caractéristique de la relaxation RMN de l'eau dans un échantillon soumis à une coagulation induite par une endotoxine afin de produire des données de relaxation RMN, et de détermination, à partir des données de relaxation RMN, d'un paramètre de résonance magnétique de l'eau dans l'échantillon, caractéristique du niveau d'endotoxine présent dans l'échantillon.
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9157974B2 (en) 2008-10-29 2015-10-13 T2 Biosystems, Inc. NMR detection of coagulation time
US9599627B2 (en) 2011-07-13 2017-03-21 T2 Biosystems, Inc. NMR methods for monitoring blood clot formation
US9739733B2 (en) 2012-12-07 2017-08-22 T2 Biosystems, Inc. Methods for monitoring tight clot formation
US10620205B2 (en) 2011-09-21 2020-04-14 T2 Biosystems, Inc. NMR methods for endotoxin analysis

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ITUA20164292A1 (it) * 2016-06-10 2017-12-10 Univ Degli Studi Di Trieste Metodo e connesso apparato per analisi di un campione di espettorato
US11099189B2 (en) * 2017-10-17 2021-08-24 Board Of Regents, The University Of Texas System Limulus amoebocyte lysate assay and method of same
CN109598245B (zh) * 2018-12-07 2023-02-07 上海理工大学 基于1d-cnn的食用油横向弛豫衰减曲线信号特征提取方法

Citations (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4101435A (en) 1975-06-19 1978-07-18 Meito Sangyo Kabushiki Kaisha Magnetic iron oxide-dextran complex and process for its production
US4452773A (en) 1982-04-05 1984-06-05 Canadian Patents And Development Limited Magnetic iron-dextran microspheres
US5204457A (en) 1989-10-20 1993-04-20 Meito Sangyo Kabushiki Kaisha Organic magnetic complex
US5262176A (en) 1986-07-03 1993-11-16 Advanced Magnetics, Inc. Synthesis of polysaccharide covered superparamagnetic oxide colloids
US5424419A (en) 1991-06-11 1995-06-13 Meito Sangyo Kabushiki Kaisha Oxidized complex comprising water-soluble carboxypolysaccharide and magnetic iron oxide
US5492814A (en) 1990-07-06 1996-02-20 The General Hospital Corporation Monocrystalline iron oxide particles for studying biological tissues
US6165378A (en) 1996-08-30 2000-12-26 Meito Sangyo Kabushiki Kaisha Polysaccharide derivative/magnetic metal oxide composite
US20030054432A1 (en) 2001-06-28 2003-03-20 Biowhittaker, Inc. Methods and reagents for detecting endotoxin
US20030092029A1 (en) 2001-06-06 2003-05-15 Lee Josephson Magneitc-nanoparticle conjugates and methods of use
US20040175388A1 (en) 1998-12-24 2004-09-09 National University Of Singapore Recombinant proteins and peptides for endotoxin biosensors, endotoxin removal, and anti-microbial & anti-endotoxin therapeutics
US6866838B1 (en) 1999-11-05 2005-03-15 Bio Merieux Composite nanospheres and their conjugates with biomolecules
US20060269965A1 (en) 2005-05-09 2006-11-30 Lee Josephson Water relaxation-based sensors
US7217457B2 (en) 2001-05-10 2007-05-15 Bio Merieux Composite particles, derived conjugates, preparation method and applications
US20070116602A1 (en) 2005-08-31 2007-05-24 Bioplex Systems Inc. NMR device for detection of analytes
WO2010002479A1 (fr) * 2008-07-03 2010-01-07 Lowery Thomas Jay Jr Compositions de nanocapteurs magnétiques et analyses bioanalytiques appropriées
WO2010051362A1 (fr) 2008-10-29 2010-05-06 T2 Biosystems, Inc. Détection par rmn du temps de coagulation
US20120000546A1 (en) * 2006-12-05 2012-01-05 David Lewis Systems and Methods for the Collection, Retention, and Redistribution of Rainwater and Methods of Construction of the Same

Family Cites Families (76)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4374360A (en) 1980-05-29 1983-02-15 Sepponen Raimo E NMR Diagnosis apparatus
US4920061A (en) 1984-03-02 1990-04-24 The University Of Texas System Biological magnetic colloids
US4875486A (en) 1986-09-04 1989-10-24 Advanced Techtronics, Inc. Instrument and method for non-invasive in vivo testing for body fluid constituents
US5136095A (en) 1987-05-19 1992-08-04 Syntex (U.S.A.) Inc. Reversible agglutination mediators
US5042488A (en) 1987-09-29 1991-08-27 The Washington University Methods employing deuterium for obtaining direct, observable deuterium magnetic resonance images in vivo and in situ
WO1990006045A2 (fr) 1988-11-21 1990-06-14 Dynal As Sondes d'acide nucleique
US5049819A (en) 1989-06-30 1991-09-17 Auburn International, Inc. Magnetic resonance analysis in real time, industrial usage mode
US5254460A (en) 1990-05-03 1993-10-19 Advanced Magnetics, Inc. Solvent mediated relaxation assay system
US5164297A (en) 1990-05-03 1992-11-17 Advanced Magnetics Inc. Solvent mediated relaxation assay system
US5445970A (en) 1992-03-20 1995-08-29 Abbott Laboratories Magnetically assisted binding assays using magnetically labeled binding members
US5445971A (en) 1992-03-20 1995-08-29 Abbott Laboratories Magnetically assisted binding assays using magnetically labeled binding members
US5637469A (en) 1992-05-01 1997-06-10 Trustees Of The University Of Pennsylvania Methods and apparatus for the detection of an analyte utilizing mesoscale flow systems
JP3362192B2 (ja) 1994-12-06 2003-01-07 味の素株式会社 検査方法及び検査薬
US6500343B2 (en) 1995-02-21 2002-12-31 Iqbal W. Siddiqi Method for mixing and separation employing magnetic particles
US6884357B2 (en) 1995-02-21 2005-04-26 Iqbal Waheed Siddiqi Apparatus and method for processing magnetic particles
US6297062B1 (en) 1996-03-07 2001-10-02 Bio-Magnetics Ltd. Separation by magnetic particles
JP2000510582A (ja) 1996-04-25 2000-08-15 ゼニコン・サイエンシーズ・コーポレーション 微粒子標識を使用した分析物アッセイ
JP3996644B2 (ja) 1996-06-07 2007-10-24 イムニベスト・コーポレイション 外部及び内部勾配を有する磁気分離
AU4043497A (en) 1996-07-29 1998-02-20 Nanosphere, Inc. Nanoparticles having oligonucleotides attached thereto and uses therefor
US6361944B1 (en) 1996-07-29 2002-03-26 Nanosphere, Inc. Nanoparticles having oligonucleotides attached thereto and uses therefor
ATE253943T1 (de) 1996-09-12 2003-11-15 Amersham Health As Markerzusammensetzungen
JP3876022B2 (ja) 1996-09-26 2007-01-31 生化学工業株式会社 血液凝固時間に影響を与える物質の定量方法
FR2758884B1 (fr) 1997-01-30 1999-04-02 Bio Merieux Procede pour isoler, notamment detecter ou quantifier un analyte dans un milieu
JP3917239B2 (ja) 1997-06-05 2007-05-23 生化学工業株式会社 血液凝固時間の測定方法
DE19822123C2 (de) 1997-11-21 2003-02-06 Meinhard Knoll Verfahren und Vorrichtung zum Nachweis von Analyten
JP2000166897A (ja) 1998-12-11 2000-06-20 Toshiba Corp Ｍｒｉ装置およびｍｒイメージング方法
US7179652B2 (en) 1999-02-22 2007-02-20 Haemoscope Corporation Protocol for monitoring platelet inhibition
DK1169062T3 (da) 1999-04-09 2010-01-25 Amag Pharmaceuticals Inc Varmestabile overtrukne kolloide jernoxider
JP2003503699A (ja) 1999-06-25 2003-01-28 ナノスフェアー インコーポレイテッド オリゴヌクレオチドが付着しているナノ粒子およびその利用法
AU6828500A (en) 1999-08-06 2001-03-05 Institut Fur Diagnostikforschung Gmbh An Der Freien Universitat Berlin Method for detecting binding reactions through measurement of the relaxation of birefringence of magnetic nanoparticles
BR0014252A (pt) 1999-09-14 2002-11-19 Biomedical Apherese Systeme Gm Nanopartìculas magnéticas tendo atividade bioquìmica, método para sua produção e seus usos
US6294342B1 (en) 1999-09-29 2001-09-25 Abbott Laboratories Magnetically assisted binding assays utilizing a magnetically responsive reagent
US6307372B1 (en) 1999-11-02 2001-10-23 Glaxo Wellcome, Inc. Methods for high throughput chemical screening using magnetic resonance imaging
US6254830B1 (en) 1999-11-05 2001-07-03 The Board Of Governors For Higher Education, State Of Rhode Island And Providence Plantations Magnetic focusing immunosensor for the detection of pathogens
US6940378B2 (en) 2001-01-19 2005-09-06 Halliburton Energy Services Apparatus and method for magnetic resonance measurements in an interior volume
WO2002086500A2 (fr) 2001-04-23 2002-10-31 Metabometrix Limited Procedes d'analyses de donnees spectrales et leurs applications: atherosclerose et coronaropathie
FR2832507B1 (fr) 2001-11-20 2004-02-20 Stago Diagnostica Methode de detection d'analyte(s) a l'aide de particules magnetiques colloidales
US7018849B2 (en) 2002-01-15 2006-03-28 Piasio Roger N Process for (A) separating biological/ligands from dilute solutions and (B) conducting an immunochromatographic assay thereof employing superparamagnetic particles throughtout
CA2418229A1 (fr) 2002-05-16 2003-11-16 Rohan Dharmakumar Structure a microbulles pour manometrie a resonance magnetique amelioree
US6798200B2 (en) 2002-06-03 2004-09-28 Long-Sheng Fan Batch-fabricated gradient and RF coils for submicrometer resolution magnetic resonance imaging and manipulation
US7217542B2 (en) 2002-10-31 2007-05-15 Hewlett-Packard Development Company, L.P. Microfluidic system for analyzing nucleic acids
WO2005061724A1 (fr) 2003-12-10 2005-07-07 The General Hospital Corporation Conjugues nanoparticulaires a auto-assemblage
EP1735668A2 (fr) 2004-04-13 2006-12-27 President And Fellows Of Harvard College Procedes et appareils pour la manipulation et/ou la detection d'echantillons biologiques et d'autres objets
CN1957251B (zh) 2004-05-18 2010-11-03 皇家飞利浦电子股份有限公司 用于改善生物传感中背景上信号的磁致旋转
DE102004059055A1 (de) 2004-12-07 2006-06-08 Dade Behring Marburg Gmbh Verfahren zur automatischen Bestimmung des endogenen Thrombinpotenzials
US7781228B2 (en) 2005-04-07 2010-08-24 Menon & Associates, Inc. Magnetic resonance system and method to detect and confirm analytes
KR20080023292A (ko) 2005-05-27 2008-03-13 더 보드 오브 리전츠 오브 더 유니버시티 오브 텍사스 시스템 세포 및 조성물의 광 간섭성 단층 촬영 검출
FR2894970B1 (fr) 2005-12-15 2008-01-25 Biomerieux Sa Procede de preparation de particules composites, particules composites obtenues et leur utilisation dans un test diagnostic
US7274191B2 (en) 2005-12-29 2007-09-25 Intel Corporation Integrated on-chip NMR and ESR device and method for making and using the same
US20070166730A1 (en) 2006-01-19 2007-07-19 Menon & Associates, Inc. Magnetic resonance system and method to detect and confirm analytes
US20080261261A1 (en) 2006-03-31 2008-10-23 Kmg2 Sensors Corporation System/unit and method employing a plurality of magnetoelastic sensor elements for automatically quantifying parameters of whole blood and platelet-rich plasma
WO2008010111A2 (fr) 2006-06-21 2008-01-24 Spinomix S.A. Dispositif et procédé de manipulation et de mélange de particules magnétiques dans un milieu liquide
US8339135B2 (en) 2006-08-21 2012-12-25 Stc.Unm Biological detector and method
TWI322793B (en) 2006-10-02 2010-04-01 Chung Cheng Inst Of Technology Nat Defense University Functionalized magnetizable microspheres and preparation thereof
WO2008057578A1 (fr) 2006-11-08 2008-05-15 T2 Biosystems, Inc. Systemes rmn de detection d'analytes in vivo
WO2008072156A2 (fr) 2006-12-12 2008-06-19 Koninklijke Philips Electronics N. V. Capteur microélectronique pour détecter des particules de marquage
US8703634B2 (en) 2007-02-21 2014-04-22 The Regents Of The University Of California Hemostatic compositions and methods of use
JP2008209350A (ja) 2007-02-28 2008-09-11 Matsushita Electric Ind Co Ltd 血液凝固時間測定装置
US20100207631A1 (en) 2007-03-27 2010-08-19 Mcdowell Andrew F System and Method for Detecting Labeled Entities Using Microcoil Magnetic MRI
US8067938B2 (en) 2007-05-03 2011-11-29 Abqmr, Inc. Microcoil NMR detectors
US20110020785A1 (en) 2007-07-26 2011-01-27 T2 Biosystems, Inc. Diagnostic Information Generation and Use
US20110070657A1 (en) 2007-08-17 2011-03-24 The General Hospital Corporation Detecting ions and measuring ion concentrations
CA2700970A1 (fr) 2007-09-28 2009-04-09 T2 Biosystems, Inc. Diagnostic par rmn utilisant un recipient d'echantillons en plastiques
WO2009045551A1 (fr) 2007-10-04 2009-04-09 The General Hospital Corporation Systèmes et procédés à résonance magnétique miniaturisés
JP5539889B2 (ja) 2007-10-23 2014-07-02 アブクマー インコーポレイテッド マイクロコイル磁気共鳴検出器
WO2009061481A1 (fr) 2007-11-06 2009-05-14 T2 Biosystems, Inc. Petit aimant et bobine de radiofréquence pour une relaxométrie à résonance magnétique
JP5403516B2 (ja) * 2007-11-12 2014-01-29 国立大学法人広島大学 エンドトキシンの濃度測定方法および濃度測定用キット
EP2905631A1 (fr) 2007-12-21 2015-08-12 T2 Biosystems, Inc. Système de résonance magnétique avec composants implantables et leurs procédés d'utilisation
CA2638697C (fr) 2008-08-15 2014-11-18 Schlumberger Canada Limited Methode de determination in situ de la viscosite d'echantillons de petrole lourd au moyen de mesures du temps de relaxation en resonance magnetique nucleaire
CN101659202A (zh) 2008-08-28 2010-03-03 比亚迪股份有限公司 一种混合动力驱动系统及其驱动方法
US8563298B2 (en) 2010-10-22 2013-10-22 T2 Biosystems, Inc. NMR systems and methods for the rapid detection of analytes
US9714940B2 (en) 2010-10-22 2017-07-25 T2 Biosystems, Inc. NMR systems and methods for the rapid detection of analytes
EP3321373B1 (fr) 2011-07-13 2020-01-15 T2 Biosystems, Inc. Procédés de rmn destinés à surveiller la formation d'un caillot sanguin
WO2013043858A1 (fr) 2011-09-21 2013-03-28 T2 Biosystems, Inc. Procédés de rmn pour une analyse d'endotoxine
EP2677037B1 (fr) 2012-06-21 2016-04-13 Synapse B.V. Mesure simultanée de la génération de thrombine et résistance des caillots dans du plasma et du sang entier
WO2014004573A1 (fr) 2012-06-25 2014-01-03 T2 Biosystems, Inc. Dispositif portatif pour analyse par rmn de modifications rhéologiques dans des échantillons liquides

Patent Citations (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4101435A (en) 1975-06-19 1978-07-18 Meito Sangyo Kabushiki Kaisha Magnetic iron oxide-dextran complex and process for its production
US4452773A (en) 1982-04-05 1984-06-05 Canadian Patents And Development Limited Magnetic iron-dextran microspheres
US5262176A (en) 1986-07-03 1993-11-16 Advanced Magnetics, Inc. Synthesis of polysaccharide covered superparamagnetic oxide colloids
US5204457A (en) 1989-10-20 1993-04-20 Meito Sangyo Kabushiki Kaisha Organic magnetic complex
US5492814A (en) 1990-07-06 1996-02-20 The General Hospital Corporation Monocrystalline iron oxide particles for studying biological tissues
US5424419A (en) 1991-06-11 1995-06-13 Meito Sangyo Kabushiki Kaisha Oxidized complex comprising water-soluble carboxypolysaccharide and magnetic iron oxide
US6165378A (en) 1996-08-30 2000-12-26 Meito Sangyo Kabushiki Kaisha Polysaccharide derivative/magnetic metal oxide composite
US20040175388A1 (en) 1998-12-24 2004-09-09 National University Of Singapore Recombinant proteins and peptides for endotoxin biosensors, endotoxin removal, and anti-microbial & anti-endotoxin therapeutics
US7001589B2 (en) 1999-11-05 2006-02-21 Bio Merieux Composite nanospheres and their conjugates with biomolecules
US6866838B1 (en) 1999-11-05 2005-03-15 Bio Merieux Composite nanospheres and their conjugates with biomolecules
US7217457B2 (en) 2001-05-10 2007-05-15 Bio Merieux Composite particles, derived conjugates, preparation method and applications
US20030092029A1 (en) 2001-06-06 2003-05-15 Lee Josephson Magneitc-nanoparticle conjugates and methods of use
US20030054432A1 (en) 2001-06-28 2003-03-20 Biowhittaker, Inc. Methods and reagents for detecting endotoxin
US20060269965A1 (en) 2005-05-09 2006-11-30 Lee Josephson Water relaxation-based sensors
US20070116602A1 (en) 2005-08-31 2007-05-24 Bioplex Systems Inc. NMR device for detection of analytes
US7564245B2 (en) 2005-08-31 2009-07-21 T2 Biosystems, Inc. NMR device for detection of analytes
US20120000546A1 (en) * 2006-12-05 2012-01-05 David Lewis Systems and Methods for the Collection, Retention, and Redistribution of Rainwater and Methods of Construction of the Same
WO2010002479A1 (fr) * 2008-07-03 2010-01-07 Lowery Thomas Jay Jr Compositions de nanocapteurs magnétiques et analyses bioanalytiques appropriées
WO2010051362A1 (fr) 2008-10-29 2010-05-06 T2 Biosystems, Inc. Détection par rmn du temps de coagulation

Non-Patent Citations (11)

* Cited by examiner, † Cited by third party
Title
BERGMAN ET AL., PHYS. REV. E, vol. 51, 1995, pages 3393 - 3400
BLINC, A. ET AL., MAGNETIC RESONANCE IN MEDICINE, vol. 14, 1990, pages 105 - 122
EDZES,./., MAGN. RESON., vol. 17, 1975, pages 301 - 313
ISTRATOV, A. A.; VYVENKO, O. F., REV. SEI. INST., vol. 70, 1999, pages 1233
LUPU, M.; TODOR, D., CHEMOMETRICS AND INTELLIGENT LABORATORY SYSTEMS, vol. 29, 1995, pages 11
MOLDAY, R. S.; D. MACKENZIE: "Immunospecific ferromagnetic iron-dextran reagents for the labeling and magnetic Separation of cells", J. IMMUNOL. METHODS, vol. 52, 1982, pages 353
PROVENCHER, S. W., COMP. PHYS. COMM., vol. 27, 1982, pages 213
PROVENCHER, S. W.; VOGEL, R. H., MATH. BIOSCI., vol. 50, 1980, pages 251
See also references of EP2748651A4
SEZGINER ET AL., J. MAGN. RESON., vol. 92, 1991, pages 504 - 527
VIDMAR ET AL., NMR BIOMED., vol. 23, 2010, pages 34 - 40

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9157974B2 (en) 2008-10-29 2015-10-13 T2 Biosystems, Inc. NMR detection of coagulation time
US10126314B2 (en) 2008-10-29 2018-11-13 T2 Biosystems, Inc. NMR detection of coagulation time
US9599627B2 (en) 2011-07-13 2017-03-21 T2 Biosystems, Inc. NMR methods for monitoring blood clot formation
US9797914B2 (en) 2011-07-13 2017-10-24 T2 Biosystems, Inc. NMR methods for monitoring blood clot formation
US10697984B2 (en) 2011-07-13 2020-06-30 T2 Biosystems, Inc. NMR methods for monitoring blood clot formation
US10620205B2 (en) 2011-09-21 2020-04-14 T2 Biosystems, Inc. NMR methods for endotoxin analysis
US9739733B2 (en) 2012-12-07 2017-08-22 T2 Biosystems, Inc. Methods for monitoring tight clot formation

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EP2748651A1 (fr) 2014-07-02
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US20140220594A1 (en) 2014-08-07
US10620205B2 (en) 2020-04-14

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